Instrument for inserting intraocular lens

ABSTRACT

An intraocular lens insertion instrument capable of smoothly pushing out a preset lens is provided. An intraocular lens insertion instrument ( 1 ) comprises: a main body ( 3 ) including a lens setting section ( 8 ) on which a lens ( 2 ) is set, a transition section ( 22 ) that deforms the lens ( 2 ), and a nozzle piece ( 21 ) that releases the lens ( 2 ); and a lens push-out mechanism ( 4 ) that pushes out the lens ( 2 ) set on the lens setting section ( 8 ). The instrument ( 1 ) further includes a releasing means ( 11 ) for releasing the lens ( 2 ) pushed by the lens push-out mechanism ( 4 ) from the lens setting section ( 8 ). The releasing means ( 11 ) has a posture holding mount ( 12 ) that holds the lens ( 2 ) with a forward tilt relative to an axial line (A) of lens movement. The posture holding mount ( 12 ) has a passage ( 15 ) through which the lens push-out mechanism ( 4 ) passes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/095,172, filed May 28, 2008 now U.S. Pat. No. 8,523,941, which wasthe U.S. national phase under 35 U.S.C. §371 of PCT InternationalApplication No. PCT/JP2006/324054, which has an International filingdate of Dec. 1, 2006, and claims the benefit of Japanese Application No.2005-354968, filed Dec. 8, 2005, each of which are incorporated byreference herein.

TECHNICAL FIELD

The present invention relates to an intraocular lens insertioninstrument used to insert an intraocular lens into an aphakic eye aftercataract surgery or to an intraocular lens insertion instrument used toinsert an intraocular lens to a phakic eye during refractive surgery.More specifically, the present invention relates to a preset intraocularlens insertion instrument wherein a lens has been preset in an injector.

BACKGROUND ART

In cataract surgery, there has been widely performed removal ofopacified lenses by phacoemulsification (PEA) followed by implantationof intraocular lenses into aphakic eyes. Intraocular lenses areclassified into hard intraocular lenses whose optics are made of a hardmaterial such as PMMA and soft intraocular lenses whose optics are madeof a flexible material such as silicone elastomer or soft acrylic. Uponuse of a hard intraocular lens, the lens needs to be inserted through anincision having been cut in a cornea or sclera in a width approximatelythe same as the diameter of the optic of the lens. On the other hand, byfolding the optic of a soft intraocular lens, the lens can be insertedthrough an incision smaller than the diameter of the optic. In order toreduce the risk of post-surgery cornea astigmatism or infection,insertion of a lens through a small incision is preferable.Consequently, soft intraocular lenses tend to be preferred. In addition,dedicated injectors having a mechanism to lead a lens to an eye througha slender tube are used in some cases in order to insert lenses intoeyes. By using such injectors dedicated to intraocular lens insertion, alens can be inserted through an incision smaller than 3 mm.

Recently, in order to eliminate the possibility of microbialcontamination and operational mishandling at the time of dealing withlenses, preset injectors having lenses preset therein have beenavailable on the market. Some of such preset injectors have a lensholding mechanism and a lens moving mechanism. The lens holdingmechanism holds a lens inside of an injector in a state of non-stress onthe optic of the lens so that the lens can be changed from a stationarystate at the time of shipment to an operable state upon use. The lensmoving mechanism moves the lens to a position where the lens can bemoved by a push-out mechanism (see Patent Documents 1 and 2, forexample).

-   Patent Document 1: Japanese Patent Application Laid-Open (JP-A)    Publication No. 2003-325570-   Patent Document 2: JP-A No. 2003-325572

DISCLOSURE OF INVENTION Problems to be Solved by the Invention

Nonetheless, the moving mechanism to move the lens from the presetposition to the releasable position is complex in the preset injectorsdescribed in the above-mentioned Patent Documents 1 and 2, whichincreases the production cost thereof. Moreover, the possibility ofmalfunctioning is not eliminated. In order to solve these problems, theinventors of the invention have invented a mechanism whereby a lens canbe pushed out as it is at a preset position.

However, even in this mechanism, the lens may stick to the settingsection in the case where an intraocular lens has been stored in closecontact with a lens setting section of an injector. In this case, thelens is stressed excessively if the lens is pushed out parallel to asurface thereof, and may be damaged or become behaviorally unstable.Specifically, in the case where the lens is made of a soft acrylicmaterial or a silicone material, the lens tends to stick more to thelens setting section. Furthermore, in a combination of the lens made ofsuch a material and polypropylene or polyethylene generally used as amaterial of disposable injectors, the lens tends to stick even more tothe lens setting section.

The present invention has been conceived in view of the above-mentionedproblems, and an object of the present invention is therefore to providean intraocular lens insertion instrument that enables smooth push-outoperation of a preset lens.

Means for Solving the Problems

In order to achieve the object described above, the invention accordingto a first aspect thereof is an intraocular lens insertion instrumenthaving: a main body comprising a lens setting section for setting anintraocular lens thereon, a transition section for deforming theintraocular lens, and a nozzle piece for discharging the intraocularlens; and a lens push-out mechanism for pushing out the intraocular lensset on the lens setting section, characterized in that the instrumentfurther comprises a releasing means for releasing the intraocular lenspushed by the lens push-out mechanism from the lens setting section.

The invention according to a second aspect thereof is characterized inthat the releasing means has a posture holding mount for holding thelens with a forward tilt relative to an axial line of lens movement.

The invention according to a third aspect thereof is characterized inthat the posture holding mount has a passage through which the lenspush-out mechanism passes.

The invention according to a fourth aspect thereof is characterized inthat the lens push-out mechanism has a scooping surface for scooping thelens.

Effects of the Invention

According to the intraocular lens insertion instrument as the firstaspect of the invention, the presence of the releasing means enables thelens in close contact with the lens setting section to be released fromthe lens setting section when the lens push-out mechanism pushes thelens. Therefore, the lens can be pushed out smoothly, and damage to thelens and unstable behavior of the lens can be prevented.

According to the intraocular lens insertion instrument as the secondaspect of the present invention, the presence of the posture holdingmount enables the lens to be held with the forward tilt relative to theaxial line of lens movement. Therefore, when the lens push-out mechanismpushes the lens, the rear end of the lens is lifted, enabling air tomove in between the lens and the lens setting section. In this manner,the lens can be released from the lens setting section and pushed outsmoothly.

According to the intraocular lens insertion instrument as the thirdaspect of the present invention, the presence of the passage preventsthe posture holding mount from hindering movement of the lens push-outmechanism at the time the lens push-out mechanism pushes the lens out.Therefore, the lens can be pushed out more smoothly.

According to the intraocular lens insertion instrument as the fourthaspect of the present invention, scooping the rear end of the lens bythe scooping surface at the time of lens push-out enables air to move inbetween the lens and the lens setting section. Consequently, the lens isreleased from the lens setting section and can be pushed out moresmoothly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the overall structure of an intraocular lens insertioninstrument of the present invention, in which (A) is a front viewthereof and (B) is a plan view thereof.

FIG. 2 is a perspective view showing the structure around a lens settingsection.

FIG. 3 shows the structure of the lens setting section, in which (A) isa longitudinal cross-sectional view thereof while (B) is a transversecross-sectional view thereof.

FIG. 4 shows modifications to a lens contact area, in which (A) is alongitudinal cross-sectional view thereof with a protruding lower endwhile (B) is a longitudinal cross-sectional view thereof with adiagonally cut lower end.

FIG. 5 is a perspective view showing a state in which a lens has beenset on the lens setting section.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a preferred embodiment of the present invention will bedescribed with reference to the accompanying drawings.

An intraocular lens insertion instrument 1 shown in FIG. 1 is used todischarge a deformable intraocular lens 2 (hereinafter simply referredto as the lens 2) safely and swiftly into an eye. The intraocular lensinsertion instrument 1 is specifically a preset intraocular lensinsertion instrument in which the lens 2 has been preset inside theinstrument 1. More specifically, the intraocular lens insertioninstrument 1 comprises a main body 3 that houses the lens 2 and insertsthe lens 2 into an eye, and a lens push-out mechanism 4 that pushes outthe lens 2. In this embodiment, a lens having an optic 2 a and loopedhaptic elements 2 b is used as the lens 2.

The main body 3 comprises a tubular proximal member 5 and a distalmember 6 whose tapered end is relatively narrower than the proximalmember 5. The proximal member 5 and the distal member 6 are united witheach other in a detachable manner in an engagement section 7. Variousmaterials can be used for the main body 3. For example, not only a metalsuch as stainless steel or titanium but also a synthetic resin or thelike can be used for the main body 3.

The proximal member 5 has a lens setting section 8 at one end thereofand a slit 9 formed in a tubular sidewall thereof along a longitudinaldirection thereof. Engagement projections 10 to engage with a grip unitthat will be described later are formed on an outer periphery surface ofthe proximal member 5. The slit 9 is formed between an edge of the oneend and a substantial center of the proximal member 5.

The intraocular lens insertion instrument 1 has a releasing means 11 asshown in FIG. 2, whereby the lens 2 in close contact with the lenssetting section 8 can be released and moved smoothly at the time thelens push-out mechanism 4 pushes the lens 2 having been set on the lenssetting section 8.

The releasing means 11 releases the lens 2 from the lens setting section8 by pushing forward the lens 2 stored on the lens setting section 8with a forward tilt. The releasing means 11 comprises the lens push-outmechanism 4 and a posture holding mount 12 for holding the lens 2 on thelens setting section 8 with the forward tilt.

The lens setting section 8 comprises a setting section body 13protruding from the one end of the proximal member 5, the postureholding mount 12 formed on an upper surface of the section body 13, andsidewalls 14 formed outside the posture holding mount 12. The settingsection body 13 is made of a plate member whose surface is smooth andparallel to an axial line A of lens movement so that the lens 2 setthereon can be held stably.

The posture holding mount 12 is configured so as to hold the lens 2 withthe forward tilt. On an upper surface of the posture holding mount 12,the mount 12 has slopes 12 a inclined downward toward the distal end ofthe lens setting section 8. A passage 15 through which the lens push-outmechanism 4 passes is also provided in the center of the posture holdingmount 12. The passage 15 comprises an elongated groove that is parallelto the axial line A of lens movement.

The sidewalls 14 are formed so that the center of the lens 2 can alignwith the axial line A of lens movement. The sidewalls 14 can alsoprevent the lens 2 from falling sideways when the lens 2 is placed onthe lens setting section 8. Therefore, assembling the instrument becomeseasy. The sidewalls 14 are made of plate members that protrude from bothsides of the setting section body 13 and are elongated along alongitudinal direction of the body 13.

The distal member 6 comprises a nozzle piece 21 for inserting the lens 2set on the lens setting section 8 into an eye, and a transition section22 that connects the nozzle piece 21 with the proximal member 5. Thetransition section 22 is substantially funnel-shaped, tapering towardthe distal end thereof, and connects the nozzle piece 21 at the distalend. The nozzle piece 21 is formed in such a size that an outsidediameter thereof enables insertion thereof into an incision. The lens 2is folded while passing through the transition section 22 by beingpushed by the lens push-out mechanism 4. The distal member 6 also has astopper 23 for stopping a hereinafter-described slider, at apredetermined position. The stopper 23 comprises projections that lock ahereinafter-described handling element of the slider.

As shown in FIG. 1, the lens push-out mechanism 4 comprises the slider25 used for an initial operation to insert the lens 2, and a plunger 26for inserting the lens 2 into an eye.

The plunger 26 is to insert the lens 2 folded by the slider 25 into aneye, and comprises a push rod 27 for pushing out the lens 2 and the gripunit 28 located at the proximal end of the push rod 27. The push rod 27is loosely fitted into a hole 29 formed in the grip unit 28, andpivotally supported by the grip unit 28 at the bottom of the hole 29. Afemale screw 29 a is formed in the hole 29. The female screw 29 a formedin the grip unit 28 is to be screwed together with the engagementprojections 10. The engagement projections 10 are made up of portions ofa male screw that is to be screwed into the female screw 29 a. Formingthe engagement projections 10 as the male screw portions enables notonly preventing of the engagement projections 10 from interfering withthe slit 9 or the like but also secure screwing into the female screw 29a for pushing in the grip unit. The grip unit 28 thus pushes the pushrod 27 along the axial line A of lens movement. The grip unit 28 isformed into a shape that enables easy push of the plunger 26.

As shown in FIG. 3, the slider 25 is formed so as to enable the lens 2set on the lens setting section 8 to be pushed out toward the distal endof the main body 3 without local stress on the lens 2 and to be foldedin a predetermined direction. The slider 25 engages with the slit 9 inthe main body 3. The slider 25 comprises a slider body 30 that supportsthe slider 25 along the axial line A of lens movement, a lens contactarea 31 in contact with the lens 2 in an area larger than the plunger26, a guide groove 32 that supports the plunger 26 along the axial lineA of lens movement and functions as an insertion passage, and alooped-element guide 34 that catches one of the looped haptic elements 2b of the lens 2.

The lens contact area 31 is formed by an arc whose curvature radius issubstantially the same as that of the outside diameter of the lens 2.The form of the lens contact area 31 enables smooth execution of theinitial operation without locally stressing the lens 2, by contactingthe lens 2 in a larger area.

The lens contact area 31 also has a scooping surface 31 a. The scoopingsurface 31 a enables scooping of the rear end of the lens 2 set on thelens setting section 8. The scooping surface 31 a is shaped into adownward slope toward the distal end thereof. By having the slopedshape, the scooping surface 31 a can gradually scoop up the lens 2,which enables more secure release of the lens 2.

As shown in FIG. 4(A), the scooping surface 31 a may protrude from thelower end of the lens contact area 31. By having the protrusion at thedistal end of the scooping surface 31 a, the end of the scooping surface31 a can be pushed in between the lens 2 and the lens setting section 8.Consequently, air can move to around the center of the lens 2, enablingthe lens 2 to be easily released from the lens setting section 8.

Alternatively, the scooping surface 31 a may be formed to have awedge-like shape, as shown in FIG. 4(B). By pushing in the wedge-shapedscooping surface 31 a between the lens 2 and the lens setting section 8,the rear end of the lens 2 can be lifted upward. Consequently, the lens2 can be easily released from the lens setting section 8.

The guide groove 32 is formed so as to allow the plunger 26 to slidethereon, and to allow the distal end of the plunger 26 to protrude fromthe lens contact area 31. The guide groove 32 is formed substantially inthe center of one surface of the slider 25 over the entire lengththereof, and comprises a groove that is parallel to the axial line A oflens movement. A cross section of the guide groove 32 is formedsubstantially in the same shape as the contour of the plunger 26. Afan-shaped leading passage 21 a is formed at the proximal end of theguide groove 32. Thus, the push rod 27 is inserted through the guidegroove 32 formed in the slider 25, and slides within the guide groove 32in a longitudinal direction of the slider 25. Alternatively, the guidegroove 32 may be a hole that pierces parallel to the axial line A oflens movement.

The slider body 30 enables the slider 25 to be held substantially in thecenter of the main body 3 while enabling the slider 25 to move along theaxial line A of lens movement, by engaging with the slit 9. Therefore,the plunger 26 is held in the center of the main body 3, and movablealong the axial line A of lens movement due to the presence of the guidegroove 32. The handling element 33 enables easy movement of the slider25.

The looped-member guide 34 is formed on another surface of the slider 25on which the guide groove 32 is not formed. The looped-element guide 34fixes the lens 2 by catching one of the looped haptic elements 2 b. Thelooped-member guide 34 is formed by a groove similar to the curvature ofthe looped haptic elements 2 b. The looped-member guide 34 is formed inthe curvature on the side of the distal end of the slider 25 so as notto physically stress the looped haptic elements 2 b.

As shown in FIG. 5, the slider 25 has the handling element 33 forpushing the slider 25 in and out. The handling element 33 is a pairlocated on right and left sides of the axial line A of lens movement,and connected to an end of the slider body 30 while protruding from theproximal member 5. The handling element 33 is formed so as to bulge morewhen viewed toward the distal end of the main body 3. Although not shownin the drawings, the handling element 33 may have a corrugated surfaceformed by a plurality of grooves that are substantially perpendicular tothe axial line A of lens movement. Alternatively, an arrow indicating adirection of movement may be shown on the surface.

Procedures of assembling the intraocular lens insertion instrument 1 ofthe above configuration will be described next. The slider 25 is firstlyattached to the proximal member 5. In order to join the slider 25 andthe proximal member 5, the slider body 30 is engaged with the slit 9from the one end of the proximal member 5, and the slider 25 is pushedin to the proximal end of the slit 9. The plunger 26 is then insertedfrom the other end of the proximal member 5. At this time, the distalend of the plunger 26 is aligned with a position where the distal enddoes not project beyond the distal end of the slider 25 having been setin the proximal member 5. Thereafter, as shown in FIG. 3, one of thelooped haptic elements 2 b of the lens 2 is caught by the looped-elementguide 34 of the slider 25, and the lens 2 is set on the lens settingsection 8. At this time, as shown in FIG. 3(A), the lens 2 is held withthe forward tilt by being set on the posture holding mount 12. Bykeeping the forward tilt of the lens 2, the looped haptic element 2 b atthe rear is set above the lens push-out mechanism 4. Furthermore, sincethe lens setting section 8 has the sidewalls 14, the center of the lens2 can be easily aligned with the axial line A of lens movement.Thereafter, as shown in FIG. 5, the distal member 6 is united with theproximal member 5 in the engagement section 7. In this manner, theintraocular lens insertion instrument 1 can be securely assembledwithout stress on the lens 2.

Operation of the above configuration will be described next. The lens 2has been set on the lens setting section 8 for some time, and in closecontact with the lens setting section 8. Firstly, an operator holds thehandling element 33 and pushes the slider 25 forward. When the slider 25is pushed forward, the lens contact area 31 touches the lens 2. When theoperator pushes the slider 25 forward in a state where the lens 2 is incontact with the lens contact area 31, the rear of the lens 2 is liftedsince the lens 2 is held with the forward tilt. When the rear of thelens 2 is lifted, air comes in between the lens 2 and the lens settingsection 8, releasing the lens 2 having been in close contact with thelens setting section 8 from the lens setting section 8. By pushing theslider 25 until the slider 25 hits the stopper that is not shown in FIG.5, the lens 2 can be pushed out to the transition section 22.

When the slider 25 hits the stopper 23 and stops, the operator pushesthe plunger 26. In order to push the plunger 26, the operator pushes thegrip unit 28 to cause the female screw 29 a to engage with theengagement projections 10 by screwing. Thereafter, the operator turnsthe grip unit 28. While being turned, the grip unit 28 moves from theproximal end of the proximal member 5 in a direction of the axial line Aof lens movement. When the grip unit 28 is moved from the proximal endin the direction of the axial line A, the push rod 27 moves in thedirection of the axial line A by being pushed by the grip unit 28, whilepushing the plunger 26. In this manner, the lens 2 is folded whilepassing through the narrow nozzle piece 21 by being pushed by theplunger 26. By pushing the plunger 26 further in a state where the lens2 is folded in such a manner, the lens 2 is inserted into an eye.

As has been described above, according to this embodiment, theintraocular lens insertion instrument 1 has the releasing means 11 forreleasing the lens 2 pushed by the lens push-out mechanism 4 from thelens setting section 8. Therefore, the lens 2 in close contact with thelens setting section 8 can be released from the lens setting section 8when the lens push-out mechanism 4 pushes the lens 2. Consequently, thelens 2 can be pushed out smoothly, which prevents damage to the lens 2as well as unstable behavior of the lens 2.

Moreover, the releasing means 11 has the posture holding mount 12 forholding the lens 2 with the forward tilt along the direction of theaxial line A of lens movement. Therefore, when the lens push-outmechanism 4 pushes the lens 2, the rear end of the lens 2 is lifted,allowing air to come in between the lens 2 and the lens setting section8. In this manner, the lens 2 can be released from the lens settingsection 8 and pushed out smoothly.

Since the posture holding mount 12 has the passage 15 through which thelens push-out mechanism 4 passes, the posture holding mount 12 does nothinder the movement of the lens push-out mechanism 4 when the lenspush-out mechanism 4 pushes out the lens 2. Therefore, the lens 2 can bepushed out more smoothly.

Furthermore, the lens push-out mechanism 4 has the scooping surface 31 afor scooping the lens 2. Therefore, when the lens 2 is pushed out, thescooping surface 31 a scoops the rear end of the lens 2, allowing air tocome in between the lens 2 and the lens setting section 8. Consequently,the lens 2 can be released from the lens setting section 8 and pushedout smoothly.

In addition, the posture holding mount 12 is configured to support theboth sides of the lens 2. Therefore, even in the case where the lens 2has been stored for a long time, deformation of the optic 2 a can beprevented.

Since the posture holding mount 12 holds the lens 2 with the forwardtilt, the looped haptic element 2 b at the rear of the lens 2 can beplaced above the lens push-out mechanism 4. Therefore, damage to thelooped haptic elements 2 b associated with the movement of the lenspush-out mechanism 4 can be prevented.

Moreover, the lens setting section 8 has the sidewalls 14. Therefore,the lens 2 can be set easily at the center of the lens setting section8. Consequently, the center of the lens 2 agrees with the axial line Aof lens movement, which enables smoother push-out of the lens 2.

In a state of non-use, the lens 2 is in close contact with the lenssetting section 8. Therefore, the lens 2 can be held safely and securelyeven in the case where the looped haptic element 2 b is not caught bythe looped-element guide 34 of the slider 25.

The present invention is not limited to the embodiment described above,and various modifications can be made thereto within the scope of thepresent invention.

The invention claimed is:
 1. An apparatus, comprising: a main bodydefining a lens movement direction and including a lens setting section,a nozzle, and a tapered transition section between the lens settingsection and the nozzle, the lens setting section having first and secondlongitudinally extending members, separated by a groove, that each slopedownward toward the nozzle in the lens movement direction from a highestpoint to a lowest point that is distal of the highest point; anintraocular lens stored on the first and second longitudinally extendingmembers in a substantially unstressed state with an edge closest to thenozzle lower in elevation than an opposite edge farthest from thenozzle; and a plunger carried within the main body and movable in thelens movement direction to drive the intraocular lens through thenozzle.
 2. An apparatus as claimed in claim 1, wherein the lens settingsection includes first and second longitudinally extending sidewallsrespectively adjacent to the first and second longitudinally extendingmembers.
 3. An apparatus as claimed in claim 1, wherein the intraocularlens includes an optic and first and second haptics; and the intraocularlens is stored on the first and second longitudinally extending memberswith diametrically opposed edges of the optic on the first and secondlongitudinally extending members.
 4. An apparatus as claimed in claim 1,further comprising: a slider carried within the main body and movable inthe lens movement direction to drive the intraocular lens from the lenssetting section to the tapered transition section; wherein the sliderand the plunger are associated with one another such that the slider isdistally movable relative to the plunger, and the plunger is distallymovable relative to and distal of the slider.
 5. An apparatus as claimedin claim 4, wherein the slider is carried within the main body such thata portion of the slider will be located within the groove in the lenssetting section as the slider drives the intraocular lens from the lenssetting section to the tapered transition section.
 6. An apparatus asclaimed in claim 4, wherein the slider includes a lens contact area; andthe plunger is narrower than the lens contact area.
 7. An apparatus asclaimed in claim 4, wherein the slider includes a guide groove in whicha portion of the plunger is located.
 8. An apparatus as claimed in claim4, wherein the slider includes a scooping surface.
 9. An apparatus asclaimed in claim 8, wherein the intraocular lens includes an outersurface with a radius of curvature; and the slider scooping surfacecomprises an arcuate surface with a radius of curvature that issubstantially the same as the intraocular lens outer surface radius ofcurvature.
 10. An apparatus as claimed in claim 4, further comprising: aslider handle located adjacent to the main body and connected to theslider; and a plunger grip located proximal of the main body andconnected to the plunger.
 11. An apparatus as claimed in claim 10,wherein the slider handle includes first and second handle memberslocated on opposite sides of the main body.
 12. An apparatus as claimedin claim 10, wherein the plunger grip is rotatable.